Inconsistent Windows virtual machine performance when disks are located on SAN datastores

[steve72]

Hi,

Windows virtual machines may experience intermittent issues when stored on datastores presented from non-local storage. This issue may be encountered on virtual machines that use SAN, NFS or iSCSI storage.

These issues may include:
• Bluescreen errors
• Event ID: 9 messages in the Event Viewer
• This error reported in guest operating system:

The device, \Device\ScsiPort0, did not respond within the timeout period
• Virtual machine becomes unresponsive, halts, or is inaccessible from the console.

Warm regards,
Steve

[Snake08]

In almost all cases, these messages are being posted due to hardware problems with either the controller or, more likely, a device that is attached to the controller in question. The hardware problems can be associated with poor cabling, incorrect termination or transfer rate settings, lazy or slow device responses to relinquish the SCSI bus, a faulty device, or, in very rare cases, a poorly written device driver. Check this microsof guide : How to troubleshoot event ID 9

[Patio]

Windows may experience storage issues with SAN as the SAN storage is not a local hard disk. It is a network storage. I have not used SAN but as far as i understand the concept, its a cloud of a bigger storage on a local network or internet, so it is meant to be slower then the local hard disks...